Imagine for a moment describing all French wine as "French wine". It wouldn't begin to give you a sense of the diversity of what the country has to offer, or where to go for the best example of a particular type – Burgundy for chardonnay and pinot noir, for instance. Yet there's still a tendency to refer to wines from "new world" countries as South African, Argentinian and Chilean, as if there were no regional differences.

Granted, at the most basic level there aren't – wines will be sourced from whatever fruit is available at a particular price point – but spend a bit more on a bottle and you will be rewarded by the best of what the country has to offer. In South Africa, for example, it pays to be aware of which regions do what well: Constantia, Darling and Elgin are the key areas for sauvignon blanc, Hemel-en-Aarde for chardonnay and pinot, Stellenbosch for attractively supple, bordeaux-style reds, and the Swartland – South Africa's "wild west" – for syrah and chenin blanc.

Elgin is, I think, currently the most exciting or, as one winemaker put it, "the coolest area in South Africa, and not just climate-wise". To begin with, its sauvignons seemed like a crude attempt to ape the New Zealand style, with too much asparagus and green pea character. Now, though, producers are more self-confident, letting grapes ripen longer and picking later to get more complexity. Wines such as the organic Elgin Ridge 282 (£12.50 at winedirect.co.uk, £12.99 at Roberts & Henry; 14% abv), which I ordered recently in a restaurant, have real elegance and finesse, and cost no more than a supermarket sancerre.

The best-known name in the region is Paul Cluver, who also makes a good, if slightly less refined sauvignon blancunder the Ferricrete label (£11.99, Marks & Spencer; 13.5% abv) and, in the same range, a pretty, floral, off-dry riesling (£12.99, M&S; 10.5% abv) which works particularly well with Asian-style salads and noodle dishes. (Marks & Sparks also has Cluver's luscious, late-harvest riesling at £14.99.)

I also discovered a gorgeously creamy, burgundy-style chardonnay, the Kershaw Elgin Chardonnay 2012 (14% abv), which is made by an English-born master of wine, Richard Kershaw – it's a bargain at £18.99 if you're a Naked Wines "angel", £31.99 to the rest of us. Unusually for Naked Wines, it is worth the full amount, but I do find the talk of "wholesale" prices misleading – check on wine-searcher.com, as the wine may be cheaper elsewhere.